The present invention relates to an improvement in submersible vessels and, more particularly, to an improved buoyancy control system for submersible vessels which may be successfully employed with such vessels as "Dean", "Star", "Daub" and the like.
It is currently known in the art to employ a variety of buoyancy control systems. Wide use is made of buoyancy control systems built around a distensible or flexible chamber filled with a ballast liquid, such as, for example, the system described in U.S. Pat. No. 3,301,209. The latter buoyancy control system comprises a distensible or flexible chamber with distensible members connected via a system of conduits and a pump to a second, water-tight and rigid chamber. The latter may either be formed by a special tank or else it may be formed directly within the pressure hull of the vessel by installing therewithin a special rigid watertight bulkhead. Buoyancy is controlled by varying the ratio of liquid volumes in the distensible and rigid chambers, with the buoyancy being increased by transferring the liquid from the rigid chamber to the distensible chamber via the conduits against the hydrostatic pressure of the surrounding sea water exerted on the distensible member. As the distensible chamber receives additional quantities of the liquid from the rigid chamber, the former's volume increases, consequently increasing the buoyancy. To decrease the buoyancy of the submersible vessel, the liquid from the distensible chamber is driven to the rigid one by the hydrostatic pressure of the surrounding sea water to which the distensible member is exposed.
One of the disadvantages of the above-described system is associated with the need for a chamber made of a distensible material, since materials of this kind age relatively quickly and are relatively susceptible to rupture. The latter circumstance necessitates special guard arrangements to protect the distensible chamber from mechanical damage, adding to the complexity of design and increasing the weight of the buoyancy control system.
A further disadvantage of this prior art system consists in the need for precision adjustment of the chamber position: the chamber must be disposed close to the axis passing through the center of buoyancy and the center of gravity of the submersible vessel, or otherwise buoyancy regulation may be fraught with the risk of heeling or trim difference of the vessel.